Summary aiosmtpd is vulnerable to inbound SMTP smuggling. SMTP smuggling is a novel vulnerability based on not so novel interpretation differences of the SMTP protocol. By exploiting SMTP smuggling, an attacker may send smuggle/spoof e-mails with fake sender addresses, allowing advanced phishing attacks. This issue also existed in other SMTP software like Postfix (https://www.postfix.org/smtp-smuggling.html).

Details Detailed information on SMTP smuggling can be found in the full blog post (https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/) or on the Postfix homepage (https://www.postfix.org/smtp-smuggling.html). (and soon on the official website https://smtpsmuggling.com/)

Impact With the right SMTP server constellation, an attacker can send spoofed e-mails to inbound/receiving aiosmtpd instances.

aio-libs aiohttp-session version 2.6.0 and earlier contains a Other/Unknown vulnerability in EncryptedCookieStorage and NaClCookieStorage that can result in Non-expiring sessions / Infinite lifespan. This attack appear to be exploitable via Recreation of a cookie post-expiry with the same value.

aio-libs aiohttp-session contains a Session Fixation vulnerability in loadsession function for RedisStorage (see: https://github.com/aio-libs/aiohttp-session/blob/master/aiohttpsession/redisstorage.py#L42) that can result in Session Hijacking. This attack appear to be exploitable via Any method that allows setting session cookies (?session=<>, or meta tags or script tags with Set-Cookie).